Update title casing in VPN connection article

Author: v-shils

articles/vpn-gateway/site-to-site-certificate-authentication-gateway-portal.md

@@ -1,5 +1,5 @@
 ---
-title: 'Create S2S VPN Connection Between On-premises Network and Azure Virtual Network - Certificate Authentication: Azure Portal'
+title: 'Create S2S VPN Connection Between On-premises Network and Azure Virtual Network - Certificate Authentication: Azure portal'
 titleSuffix: Azure VPN Gateway
 description: Learn how to configure VPN Gateway server settings for site-to-site configurations - certificate authentication.
 author: cherylmc
@@ -346,4 +346,4 @@ Once your connection is complete, you can configure additional VPN Gateway setti
 
 * [About VPN Gateway configuration settings](vpn-gateway-about-vpn-gateway-settings.md)
 * [Configure BGP for VPN Gateway](vpn-gateway-bgp-overview.md)
-* [About highly available VPN gateway connections](vpn-gateway-highlyavailable.md)
+* [About highly available VPN gateway connections](vpn-gateway-highlyavailable.md)